Converting simulated total dry matter to fresh marketable yield for field vegetables at a range of nitrogen supply levels

Simultaneous analysis of economic and environmental performance of horticultural crop production requires qualified assumptions on the effect of management options, and particularly of nitrogen (N) fertilisation, on the net returns of the farm. Dynamic soil-plant-environment simulation models for agro-ecosystems are frequently applied to predict crop yield, generally as dry matter per area, and the environmental impact of production. Economic analysis requires conversion of yields to fresh marketable weight, which is not easy to calculate for vegetables, since different species have different properties and special market requirements. Furthermore, the marketable part of many vegetables is dependent on N availability during growth, which may lead to complete crop failure under sub-optimal N supply in tightly calculated N fertiliser regimes or low-input systems. In this paper we present two methods for converting simulated total dry matter to marketable fresh matter yield for various vegetables and European growth conditions, taking into consideration the effect of N supply: (i) a regression based function for vegetables sold as bulk or bunching ware and (ii) a population approach for piecewise sold row crops. For both methods, to be used in the context of a dynamic simulation model, parameter values were compiled from a literature survey. Implemented in such a model, both algorithms were tested against experimental field data, yielding an Index of Agreement of 0.80 for the regression strategy and 0.90 for the population strategy. Furthermore, the population strategy was capable of reflecting rather well the effect of crop spacing on yield and the effect of N supply on product grading

Report of Progress: January 1 to December 31, 1952

Each calendar year the Alaska Agricultural Experiment Station submits a Progress Report to the University of Alaska and the U. S. Department of Agriculture, the 2 cooperating agencies under which it operates. This 1952 report segregates the work of each department, reporting briefly the progress made on each project currently under investigation, contributions to scientific knowledge or to the public interest and phases of the work to receive special attention during the coming year. Due credit is given to cooperating agencies and to various station personnel where more than one department is involved on a project. Briefly reported, also, are improvements and additions to physical plant, personnel changes, publications of the station during the year, and sources of financial support.Preface -- Project reports: Soil science, Horticulture, Animal industry, Engineering, Economics, Agronomy, Entomology, Plant Pathology -- Director's comments: Personnel and organization, Physical plant, Needs of the Station, Publication

Final report on the VEGINECO project

Vegetable farming systems in Europe, Final report on the VEGINECO project

Manual on prototyping methodology and multifunctional crop rotation

This VEGINECO manual is one of a series of publications resulting from the VEGINECO project. VEGINECO specialises in producing tested and improved multi-objective farming methods for key farming practices – e.g. crop rotation, fertilisation and crop protection – to facilitate the integration of potentially conflicting objectives like economy and ecology. This report consists of two parts. The first part describes the prototyping methodology and how it was used in the VEGINECO project (Chapters 2 - 5). The second part describes the methodology for developing crop rotation strategies with examples of its application under different conditions in Europe (Chapter 6 - 11)

Pre-harvest foliar application of mineral nutrients to retard chlorophyll degradation and preserve bio-active compounds in broccoli

Foliar application of micronutrients has become a common farm management practice to increase the overall yield of various crops. However, the effects of foliar fertilization on shelf life and postharvest quality of the crops are rather under-researched. The aim of this field experiment was to evaluate the effect of foliar application of individual mineral nutrients (calcium (Ca), zinc (Zn), manganese (Mn), and iron (Fe) on pre and postharvest quality of broccoli. The broccoli plants were subjected to single foliar sprays of either Ca, Fe, Zn, or Mn, which was repeated four times during plant growth at a 1 g/kg concentration. Once harvested, the broccoli heads were refrigerated at 4 °C for 28 days. Our results indicated that foliar application of Ca, Zn, Mn, and Fe did not have a significant effect on plant growth parameters, apart from enhancing Soil Plant Analysis Development (SPAD) chlorophyll meter values. However, during postharvest, foliar application treatment showed a positive response on weight loss during storage and reduction in yellowing of the broccoli heads. Foliar treatments increased the concentration of Nitrogen (N), Phosphorus (P), Ca, Zn, Mn and Fe significantly in the broccoli head tissue. Total chlorophyll content, total phenolic compound, ascorbic acid, peroxidase activity, glucoraphanin and glucobrassicin and flavonoids were significantly increased by all foliar treatments. Crude protein content and sulforaphane were enhanced by Ca and Mn treatments. Overall, foliar application of the investigated mineral nutrients may prove beneficial in improving the shelf-life and nutrient content of broccoli during postharvest handling and storage

Variation in Broccoli Cultivar Phytochemical Content under Organic and Conventional Management Systems: Implications in Breeding for Nutrition

Organic agriculture requires cultivars that can adapt to organic crop management systems without the use of synthetic pesticides as well as genotypes with improved nutritional value. The aim of this study encompassing 16 experiments was to compare 23 broccoli cultivars for the content of phytochemicals associated with health promotion grown under organic and conventional management in spring and fall plantings in two broccoli growing regions in the US (Oregon and Maine). The phytochemicals quantified included: glucosinolates (glucoraphanin, glucobrassicin, neoglucobrassin), tocopherols (d-, c-, a-tocopherol) and carotenoids (lutein, zeaxanthin, b-carotene). For glucoraphanin (17.5%) and lutein (13%), genotype was the major source of total variation; for glucobrassicin, region (36%) and the interaction of location and season (27.5%); and for neoglucobrassicin, both genotype (36.8%) and its interactions (34.4%) with season were important. For d- and ctocopherols, season played the largest role in the total variation followed by location and genotype; for total carotenoids, genotype (8.41–13.03%) was the largest source of variation and its interactions with location and season. Overall, phytochemicals were not significantly influenced by management system. We observed that the cultivars with the highest concentrations of glucoraphanin had the lowest for glucobrassicin and neoglucobrassicin. The genotypes with high concentrations of glucobrassicin and neoglucobrassicin were the same cultivars and were early maturing F1 hybrids. Cultivars highest in tocopherols and carotenoids were open pollinated or early maturing F1 hybrids. We identified distinct locations and seasons where phytochemical performance was higher for each compound. Correlations among horticulture traits and phytochemicals demonstrated that glucoraphanin was negatively correlated with the carotenoids and the carotenoids were correlated with one another. Little or no association between phytochemical concentration and date of cultivar release was observed, suggesting that modern breeding has not negatively influenced the level of tested compounds. We found no significant differences among cultivars from different seed companies

Study on effect of integrated nutrient management on growth and yield of cauliflower (Brassica oleracea var. botrytis L.)

In order to investigate the effect of integrated nutrient management on growth and yield components in Cauliflower, Brassica oleracea var. botrytis L., cv. Pusa snowball- 16, an experiment was conducted using Randomized Block Design with two replications. The experiment comprised of 14 different treatment combinations comprising of different sources of nutrients including organic, inorganic and bio-fertilizers. The growth parameters like height of plant (12.10, 23.50 cm), number of leaves per plant (9.10, 14.40) and diameter of stem (1.20, 2.10 cm) at 40 and 60 DAT respectively, the days required for curd initiation (62.00 days), days required for curd maturity (85.70 days) and staying period of curd (9.50 days) were observed maximum in treatment combination 75 % RDF + FYM + Azotobacter + Azospirillum (T6). The yield parameters like weight of curd per plot (17.50 kg/plot) and yield per hectare (180.04 q/ha) which was increased 44.10 per cent over RDF. From the studies it can be inferred that the application of 75 % RDF + FYM along with Azospirillum and Azotobactor was found to be the most effective treatment combination for getting enhanced growth and yield in cauliflower